Conventionally, as a method for producing a scintillator using alkali halide as a base material, a vacuum evaporation method of co-evaporating alkali halide as the base material and an additive as a luminescence center in a high-temperature process under high vacuum and a single crystal production method such as Czochralski process (CZ method) have been generally employed.
In the vacuum evaporation method including the high-temperature process at equal to or higher than 600° C. under high vacuum, not only huge thermal energy is consumed but also evaporated substances adhere to various places, and thus there is a problem in that material loss is large. It is also a problem in that it is difficult to control the evaporation speed and concentration of the additive as the luminescence center.
The single crystal production method also has problems in that it is difficult to increase the size of a single crystal production device for the high-temperature process at equal to or higher than 600° C. and it is difficult to produce a large-sized scintillator sheet with uniform crystallinity.
An object of the invention is to provide a method for manufacturing alkali halide-based scintillator powder at a room temperature in the atmospheric air without any complicated condition control, high-temperature process (for example, >600° C.) under high vacuum, and the like, and a method for manufacturing a scintillator material capable of producing a large-sized scintillator sheet using the alkali halide-based scintillator powder.
In the embodiment, a method for manufacturing alkali halide-based scintillator powder comprises: adding an additive containing an ion as a luminescence center to alkali halide powder as a base material so as to be predetermined mol %; and applying mechanical energy for applying an impact force, a shearing force, a shear stress, or a friction force so as to grind or mix the alkali halide powder and the additive and dope the ion as the luminescence center into alkali halide as the base material.